Slip these wireless, rechargeable and remote-controlled, heated insoles into any pair of boots or shoes and enjoy instant, adjustable warmth with just the push of a button. Great for hunting, hiking, icefishing or just to add some soothing warmth to your favorite slippers. Your feet will never overheat, because the insoles warm up to a predetermined temperature based on your remote-control setting. Compact and durable, the remote control has a 7-ft. range and three settings: Medium (100F); High (110F); and the No Heat option conserves battery life. Once the heated insoles reach the maximum temperature, they temporarily turn themselves off. They turn themselves back on when the temperature drops just like a household thermostat. The soft, durable, customizable and water-resistant insoles contain the remote receivers that deliver the heat-adjustment signals to the full-length heat sensors. These advanced heat sensors maximize your comfort by regulating the output according to your body heat and outdoor temperatures. Internal lithium-ion batteries are rechargeable up to 500 uses. On Medium, charges last for up to five hours. Tested by SATRA for durability, heating and safety. Includes charger and a remote-control battery. Sizing Chart Men/Women Small HW20-S Medium HW20-M Large HW20-L Extra Large HW-20-XL 2X-Large HW-20-XXL